IoT

The Internet of Things (IoT) is the network of physical objects that contains embedded technology to communicate and sense or interact with their internal states or the external environment. In this course, students will use two of the most popular IoT platforms (Arduino and Raspberry Pi) to develop their own "things."

TA: None.

Textbook (required): Exploring Arduino: Tools and Techniques for Engineering Wizardry, Jeremy Blum. Publisher: Wiley; 2nd edition (Nov 19, 2019). ISBN-10 : 1119405378. ISBN-13 : 978-1119405375.

Additional materials (required): Please order the following esp32-based IoT kit ASAP (tonight): https://www.amazon.com/Freenove-ESP32-WROVER-Contained-Compatible-Bluetooth/dp/B08FM2NCST/ref=sr_1_3?crid=1002GN3GY7WHH&keywords=freenove+esp32+kit&qid=1642448301&sprefix=freenove+esp32+kit%2Caps%2C63&sr=8-3

Objectives*: At the end of the semester students will be able to:

• define the term “Internet of Things”

• state the technological trends which have led to IoT

• describe the impact of IoT on society

• define what an embedded system is in terms of its interface

• enumerate and describe the components of an embedded system

• describe the interactions of embedded systems with the physical world

• name the core hardware components most commonly used in IoT devices

• describe the interaction between software and hardware in an IoT device

• describe the role of an operating system to support software in an IoT device

• explain the use of networking and basic networking hardware

• describe the structure of the Internet

• describe the meaning of a “network protocol”

*from University of California, Irvine (www.coursera.org/specializations/iot)

• intro 

• nuts-n-bolts 

• electricity 

Assignment: getting started. Submit answers via Canvas.

1. Calculate the number of nanoseconds in (a) 0.4 s, (b) 20 ms, and (c) 15 µs.

2. Determine (a) the number of seconds in 22 µs, and (b) the work done by a constant force of 200 µN applied to a mass of 10 g for a distance of 50 m.

3. How many electrons are represented by a charge of 0.32042 pC?

4. Find v if i = 6 mA and the component is (a) absorbing power of p = 18 mW, and (b) delivering to the external circuit a power of p = 12 mW.

5. If i = 3 A and v = 6 V, find the power absorbed by the element.

6. Convert the following to scientific notation: (a) 235,000, (b) 364,000,000, (c) 0.000756, and (d) 0.00000000000016.

7. Convert the following to (regular) decimal notation: (a) 4.75 x 102, and (b) 6.8 x 10-5.

8. Are positive or negative powers of 10 used to indicate numbers less than 1?

9. Are positive or negative powers of 10 used to indicate numbers greater than 1?

10. 100 = 1. (true or false)

11. Express the following numbers in scientific notation: (a) 13,500, (b) 0.00825, (c) 95,600,000, and (d) 0.104.

12. Convert the following numbers written in scientific notation into decimal notation: (a) 4.6 x 10-7, (b) 3.33 x 103, (c) 5.4 x 108, and (d) 2.54 x 10-2.

13. Convert the following numbers to engineering notation: (a) 27,000, and (b) 0.00047.

14. (a) Convert 1,000,000 ohms to engineering notation. (b) Express that value using the appropriate prefix.

15. (a) Convert 0.015 V to engineering notation. (b) Express that value using the appropriate prefix.

16. (a) Convert 250 W to engineering notation. (b) Express that value using the appropriate prefix.

• resistors 

Assignment: resistor values. Complete the corresponding  quiz in Canvas.

Assignment: resistor ranges and colors. Complete the corresponding  quiz in Canvas.

• LTspice 

Assignment: rspice. Complete this quiz in Canvas.

The purpose of this exercise is to understand Ohm's law. You will also become familiar with LTspice for simulating circuits. (Unfortunately, the Mac UI is very different from the Windows version. The Windows UI is preferable. However, if you must use a Mac, please follow the appropriate sequence below.)

Part A Windows only

Run LTspice and create a circuit consisting of a voltage source (battery) and a resistor. Assign a value of 5 V to the battery and a value of 220 Ω to the resistor. After you wire it together, run the simulation. Question 1. Write down the values that are listed under "Operating Point." (If a negative current value for the resistor appears, please let me know and I will show you how to correct it. You should see a negative current value for the battery, however.)

Question 2. State Ohm's law and calculate the current by hand.

Question 3. Calculate the power for this circuit by hand.

Close the "Operating Point" window. Click on the middle of the wire connecting the positive end of the battery to the resistor. Question 4. What value appears?

Click on the middle of the wire connecting the negative end of the battery to the resistor. Question 5. What value for voltage appears? (If your version of LTspice does not show anything, what voltage value do you expect to appear at the negative terminal of the battery?) This illustrates that there is a voltage drop across the resistor.

Once again, click on the wire between the battery and the resistor either to the left or right of the points you clicked before for Q4. Question 6. What value appears?

Right-click on the value. Replace $ with V(n001), and press OK. Question 7. What value appears?

Right-click on the value again and change it to I(R1). Question 8. What value appears?

V(n001), I(R1), and I(V1) are variables that you can use in expressions/calculations. Question 9. Using these variables, what is the equation for power?

Change the expression to calculate power and press OK. Question 10. What value appears?

Part A Mac only

Run LTspice and create a circuit consisting of a voltage source (battery) and a resistor. Assign a value of 5 V to the battery and a value of 220 Ω to the resistor. After you wire it together, run the simulation. Question 1. In the mostly black window that appears, click on the Add Trace(s) icon. Select each one of the items in Available Data, plot the values, and write down their names and corresponding values. (If a negative current value for the resistor appears, please let me know and I will show you how to correct it. You should see a negative current value for the battery, however.)

Question 2. State Ohm's law and calculate the current by hand.

Question 3. Calculate the power for this circuit by hand.

Close mostly black plot window. Run the simulation again. Click on the middle of the wire connecting the positive end of the battery to the resistor. Question 4. What value appears in the plot window?

Click on the middle of the wire connecting the negative end of the battery to the resistor. Question 5. What value for voltage appears? (If your version of LTspice does not show anything, what voltage value do you expect to appear at the negative terminal of the battery?) This illustrates that there is a voltage drop across the resistor.

Once again, click on the wire between the battery and the resistor either to the left or right of the points you clicked before for Q4. Question 6. What value appears in the plot window?

Click on the Add Trace(s) icon in the plot window. Select V(n001), and press OK. Question 7. What value appears?

Once again, click on the Add Trace(s) icon in the plot window. This time, choose I(R1). Question 8. What value appears?

V(n001), I(R1), and I(V1) are variables that you can use in expressions/calculations. Question 9. Using these variables, what is the equation for power?

Change the expression to calculate power and press OK. Question 10. What value appears?

Part B Windows & Mac

Using the table of Standard Resistor Values (lecture slide), choose the next smallest value for the resistor. Question 11. What value did you choose?

Question 12. Calculate the current by hand.

Question 13. Calculate the power by hand.

Standard power handling sizes for resistors are ⅛ W, ¼ W, ½ W, 1 W, and 2 W. Question 14. What is smallest wattage that can be safely used in the circuit with the 220 Ω resistor?

Question 15. What is smallest wattage that can be safely used in the circuit with the next smaller resistor?

Question 16. Given the voltage in this circuit, can these wattages be safely used? Why? (Hint: See lecture slides.)

• safety 

• esp32 

Assignment: sos

S-O-S is an internationally recognized distress signal. It consists of a sequence of 3 short signals, followed by 3 long signals, followed by 3 short signals, and then a pause. This pattern is then repeated over and over (indefinitely). Write an Arduino program that blinks the onboard LED in this manner.

Your challenge is to turn the LED on no more than 3 times in the loop function. (If you cannot meet this challenge, you may turn it on 9 times in the main program loop, but will only receive partial credit.) Note a for-loop that turns on an LED once each time around for a total of 3 times turns it on 3 times (not once).

There is no reason for you to define any functions of your own (other than setup and loop). Of course, you are free to define local variables (inside functions) and global ones (outside of all functions).

Deliverables: Submit your source code and a video of your working assignment to me via Canvas.

• series vs. parallel 

• diodes (issues: 1 and 2)

• digital inputs 

• IR and PIR 

• analog I/O 

• interrupts; bitwise refresher

• timers (atmega2560 only); advanced esp32 (includes esp32 timers)

• internet: intro, more intro, esp32, web server, HTML 

• sound; audio exercise -n- bn.h

• weather assignment